Means for reproducing relative angular motion



. 1,62 '46:; May 1927 E. M. HEWLETT ET AL.

MEANS FOR REPRODUCING RELATIVE ANGULAR MOTION Filed Jan. 4, 1922 lnVeh-bors: Edward. M.Hewletb,

Waldo W. Willard,

H Their- Jqt-torneg Patented May 10, 1927.

UNITED STATES PATENT OFFICE.

'EDW'AnDM. HEWLETT AND \VALDO w. WILLARD, F SCHENECTADY, NEW YORK; A s- SIGNORS T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

MEANS FOR REPRODUCING RELATIVE ANGULAR MOTION.

Application filed January 4, 1922 This invention relates to means for .C'pl'(idueing relative angular motion and has for its ob ectth e provision of improved means fo reproduemg the relative movements of a plurality of obj ects."

,More specifically our invention relates to for-driving an object differentially in response to movcm'entsof two controlling .objectsfwith relation to each other so that 0 theidriv e n object is caused to take up a position..corresponding to the relative positions of the controlling objects. Although it has various applications, whether the movement oft-he ohjectsbe that of translation or rotation, oun nvention is particularly applicableto the control of-indicatois in response to relative-movements of two objects, such as telescopes, so as to show the angular relation of the objects -2 ou t our invention we provide an electric motor constituting a reprodueer of angularmoyement and devices driven by the ob'e'cts tending to produce .magnetic fieldsin therotorand stator elements of the greproducer displaced in; accordance with the .pos'itions 1 of isa id objects; In one embod .mjent-of our invention we rnakense of th e s oeal edtfsel yni; g e et r -v 9r; transm ti devices fon transmitting in v terms. of rotao tith z oremsnt s .f th bi o reproducing motor:- The rproducingwmotor .inone formo t our invention, has, its rotor and stator elements provided with poly-circuit armature windin g s which are electri- Fh vcally c0nnected,..-respect1ve ly,' to the selsyn generators so that uponrnovernent of the ob- ;jectstherotorof the motoris caused to take up a position with relati on to its stator which corresponds with the positional relav ,-For ;a better: understanding of our inven- ,tionreferenceishould be had. to. the accompanyihg; fdrawing ;i n-- the ,single figure of ;-which,is shown in diagrammatic form'a system for reproducing relative-angular,motion 'polycircuit"armatureiwviniiing s 9. iatd. a st t r ielmen wivi ndlags"16 and 17 are elec Serial No. 527,012.

one a coarse or slow speed dial and the other a line or high speed dial. Indicator A is provided with a coarse dial l0 actuatcd'at a. 1:2 speed with the telescopes and 'with' a line dial 10 actuated at a s uitahl'e high speed ratio with the telescopes, siich"'l'fi2zl. Indicator B is'provided with similar coarse and fine dials 11 andll'. "lhefi'ne orhigh speed dials are operated indepeni'lentlv of their cooperating coarse or lowspe'ed dials. They are used to makepossible moreiiecurate readings than can be taken on the coarsc'dials. I i 5 l i DialslO and 11 are drivenelectric driving meters or reproducersim 13, the stator and rotor elements of which are con neeted, respect-ivelyfto sel s yn 'geii'er'zito'i's or transmitting devices '1 4.-" and l5" shown"zis direct connected to telescopesA 'iind' B respectively; so as tobe'fdrit en ratio therewithff 'TheSelsy 'eneratorsf l i andfi with single phase field "windi'n' i i11y $Q.- 1. .bs g' Zd 26 u blej' o i'r' art terii tia e rrnt'si ijgqfixi metfil-e fi fifi .9. arebg h tfi 'l'enected to. rep roducihg t'rio toij si-mii iild' lgg f v The reproducin m trf zfand iaitie'pibvided with poly-circifitlarni I 21 and 22 mounted on theiriot r lei ts and with similar poly-circuitparmatureiwiiidings 23 and 24 mounted on their stator'eIementS. These'armature' windings are showiijas'threecircuit delta-connectedwindings';j vi iiidin gs 23 and 2t are electricallyconnected through busses and'e to annatui win'ding 18 of selsyn gen erator 14, whilefar pat uire windings 21 and 22 are electricalljfi nnected through buss es f, g, ai1d h t'o armature winding 19 of selsyn .generator lijipn'tlieiilriiring shaft 25 of mot or l2i is secliletl:tli e dial 10 of indicator V Cooperating 10 is a stationary pointer 26. th edrrving sha ft 27 of motor13 is secured the deal 11 of indicator 13. Cooperating with dial His a stationary pointer 2S.- Thediaisare suitably calibrated, such as in degrees and minutes of are. i

A similar system is provided for the actuation. of high speed dials lo' and ll, which system will be understood with reference to the previous description, like-parts being indicated by prime reference numerals. The generators 1st and 15 of the fine system, however, are driven by the telescopes A and B, respectively, at a high speed 72rl ratio therewith, generator '14 being driren by telescope A through apinion 3O meshing with a spur gear 3t secured to the telescope, and generator 15' being driven by telescope B through apinion 32 meshing with a spur gear 33 secured to the telescope.

As thus constructed and arranged, the operation of our invention is as follows: Voltages are induced by thc alternating current field windings 16 and. 17 of the selsyn generators 14. and 15 in the various legs of their respective cooperating armature windings 18 and 19,. which voltages are impressed on the respective armature windings of motors 12 and 13 connected thereto. Alternating currents will fiow in the rotor or stator windings or both of the motors 12 and 13 by virtue of the voltages impressed,

'and these currents will inducer. resultant alternatingsingle phase magnetic flux in the core offeach motor, which flux will interlink with both rotor and stator windings and induce electromotive forces therein.

If the rotor and stator be so angularly relatedthat these inducedelectromotive forces oppose. and 'equ'al'asnearly as possible/the voltagesirnpressed, {then the motor will he in quilibriurn'and jvithout torque, and the total current'input, "to. the motor will be a mininiuimhiit if the rotor be then turned through a. small angle, the total current input will. increase and a torque will deveiop tendin to return therotor to the said position'o equilibrium 'The rotors of the motrs, being ,free,ai' ejthiis turned until this relation. of the windings is established,

movem nt, 'fb'tf example, of! tel'emope A""witli relation to; telescope B) which movement. is'tranSmitted to generator 14,

the voltages induced in the legs of armature winding 18"are changed in value in such manner. that theytendto cause an angular displacement of the fields of the motor windings 23 and 24 connected to armature winding 18. This results in :1 corresponding rotation of the motors 12 and 13.to reestablish a coincidence of magnetic fields, and hence the condition of equilibrium described above, whereby the relations of the rotor and stator elements of motors 12 and 13 are caused to correspond with the relation of the objects and dials and 11 are turned to show the amount and direction of the movementgiven telescope A. Movement of telescope B to reestablish its positional relation with telescope A tQ-l'KlS to cause an angular displacement of the fields of. motor windings 21 and 22 connected to its generator in such direction that the motors are caused to move dials l0 and 11 back to their former-positions; Motors 12 and 13- are thus caused to be" differentially responsire to movements of the telescopes, and consequently drive dials lOandll so as to show the angular relation-of the telescopes.

Simultaneously with'the movement of the coarse dials. the line dials l0" and 11 are operated to repeat the relative movements of the telescopes at their high speed ratio.

their original angular relation"is' hottlis-" tnrb ed. tlie indicators will nofibEatl'titttd.

In the use oi" the"tele sc opcs A 'aiid B' assuming that the telescopes a'ie; u'sitioncd not far from each other, shoiiltlit (18- 5: red to des gnate; a target rowan! whLch" telescop'-A" is pointing tothc operiitorfof telescope B, it is only" i1ec'esszi ryf f6r the operator of telescope B"t6-"moi?" liis telescope until pointers 2$rangl*28"'iiidicate on dials 1'1 and lI-"apredetermined niiii'k,? stleh"" as the zero mark,- correspondingtqfadndh tron of parallelismbf' 'tliefltelese' operator of telescOpdB? will then'fknowth'at ditions. that he is 'pbinting'at tlie' siinie",ta1'- get as the operator of"t'ele'sc opc AZ-".'* The operator- 0f telescope A""w'ill lilieiv-ise be advised, of this condition by observing indicator A. VVhere' the telescopes are located" a' considerable distance apart,- how'eVen -jit may be desirable to take into-'eo'nsideration the parallax angle between them:

Obviously our inventionmay be pied to objects given movement. ar -translation; In such case the'movements (if-translation of the'objects must beconverted 'and'impartedto some object, such as-a: driy ing connection, in terms of rotation for the' 'o'p'eration of our invention.

In accordance-with the provisionsoffthe patentstatutes, we have described the principle of operation of-our'invention, together with the apparatus which we now consider to represent the bestembodiment thereof; but we desire to have-it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means.

What we claim as new and desireto secure by Letters Patent of the United States,

1. Means for reproducing relative motion comprising in combination with a plurality of independently movable objects, a reproducing device, inductively cooperating relatively movable polycircuit windings for said reproducing device, electrically inductive transmitting devices driven by said objects. polycircuitarmature windings and singlephase alternating current fields for said transmitting devices, and electrical connections between the polycircuit windings of said reproducin device and the polycircuit windings 0 said transmitting devices respectively whereby magnetic fields are produced-in the windings of said reproducmg device, said fields varying in angular position in accordance with the angular positions of said objects.

2. Means for reproducing relative motion comprising -in combination with a plurality of independently movable objects, a reproducing device, inductively cooperating relatively movable polycircuit windings for said reproducing device, a plurality of transmitting devices driven by said objects respectively, field windings -for said transmitting devices, a single-phase source of alternating current supply; for said field windings, and Iele'ctrical "connections between the polycircuit windings ofi ,said reproducing device and the polycircuit windings of said transmitting devices respectively whereby fieldsare produced in the windings of said reproducing device varying angularly in ac cordance with the angular positions of said objects and the relation of said windings thereby caused to correspond with the angular relation of said objects.

3. Means for reproducing angular motion comprising in combination with a plurality of independently movable objects, of an electric motor constituting a reproducing device, poly-circuit armature windings for the rotor and stator elements of said motor, transmitting devices driven by said objects, poly-circuit armature windings and field windings for said transmitting devices, a single-phase source of alternating current supply for said field windings, and electrical connections between the armature windings of said motor and the armature windings of said transmitting devices respectively whereby the relation of the rotor and stator elements of said motor is caused to correspond with the relation of said objects.

l. Means for differentially reproducing angular motion comprising in combination with a plurality of independently rotatable objects, a reproducing device provided with rotor and stator elements, three-circuitarmature windings on the rotor and stator elements of said reproducing device, means for applying varying voltages to the circuits of said windings to cause the fields set up by said windings to rotate upon rotation of said objects, comprising two transmitting devices, driving connections between the rotor elements of said transmitting devices and. said objects respectively, three-circuit armature windings on the stators of said transmitting devices. electrical connections between said armature windings and the windings of said reproducing device respectively, field ings on the rotor elements of 'said-" trans mitting devices, and a singlebase source of alternating current supply or said field windings whereby. voltages are induced thereby in the circuits of the respective cooperating armature windings and upon rotation of said field windings the value of said induced voltages is changed causing-rotation of the field set u by the reproducer winding connected thereto. r

. In witness whereof, we have hereunto set our hands this 3rd day of January, 1922.

EDWARD M. HEWLETT. WVALDO W. WILLARD. 

